Eau Claire county was originally set off as the Town of Clearwater in Chippewa County, in 1855. The name was changed to the Town of Eau Claire on March 31, 1856. The entire town was separated as Eau Claire County by an act of the Wisconsin State Legislature on October 6, 1856.[4][5]

There were 35,822 households out of which 30.00% had children under the age of 18 living with them, 50.60% were married couples living together, 8.60% had a female householder with no husband present, and 37.80% were non-families. 27.10% of all households were made up of individuals and 10.10% had someone living alone who was 65 years of age or older. The average household size was 2.46 and the average family size was 3.02.

In the county, the population was spread out with 23.40% under the age of 18, 17.10% from 18 to 24, 26.70% from 25 to 44, 20.50% from 45 to 64, and 12.20% who were 65 years of age or older. The median age was 32 years. For every 100 females there were 93.80 males. For every 100 females age 18 and over, there were 90.60 males.

The board meets in the Eau Claire County Courthouse in downtown Eau Claire,[9] with its weekly meetings televised on local public television and transcripts published online. Most items are approved on a "consent calendar" without discussion.[10] Public comment is limited to three minutes per individual per item.